/*
 * Copyright (c) 2019 Spotify AB.
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"): you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.spotify.heroic.usagetracking

import java.util.concurrent.TimeUnit

interface UsageTracking {
    fun reportStartup()

    fun reportClusterSize(size: Int)

    fun lookupHostname(): String? {
        val hostname: String? = System.getenv("HOSTNAME")
        if (hostname != null) {
            return hostname
        }

        val process = ProcessBuilder("hostname")
            .start()
            .also { it.waitFor(200, TimeUnit.MILLISECONDS) }

        if (process.exitValue() == 0) {
            return process.inputStream.bufferedReader().readText()
        }

        return null
    }
}
